and the fraternity that i focused on in my books, sigma alpha epsilon, it banned pledging three and a half years ago. before then it was the deadliest fraternity in america. it happened more deaths, ten over almost a decade. since then it hasn't had any deaths, and its race of injuries have declined more than 90%. so there is some evidence that that is a step that would make some difference. >> yang: one case that's getting a lot of attention is penn state. new charges have been filed. is that going to be enough to drive changes in fraternity life on other campuses? >> the penn state case is so horrifying on the one hand, because you have a young man forced to drink until he can barely stand and then fall down a flight of stairs while his "brothers," so to speak, refuse to call for help over an entire night, and he dies of traumatic brain injuries. it's appalling. but what was really special about penn state is the documentation. they had surveillance footage of what happened, and just over the last week, the prosecutors found out that they had been misled by the police that there was